Temperature Sensor Two-Piece Housing Segmentation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing temperature sensors for household appliances face challenges in meeting industry safety standards while maintaining a fast thermal time constant and minimizing material costs, as they require either thick dielectric housings or time-consuming dual insulation processes.

Innovation Solution

A two-piece housing structure with a 1 mm thick bottom shell and a top connector, where the temperature responsive element is covered by epoxy, providing a two-layer dielectric insulation that meets safety standards and allows for efficient manufacturing in high-volume production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a thick dielectric housing (minimum 2 mm wall thickness) is used to meet safety standards, then the safety and insulation requirements are satisfied, but the thermal time constant increases (slows down) and material costs increase

Engineering Contradiction:

Improvesafety standard complianceVSAvoidthermal time constant

Core Design Contradiction:

ReliabilityVSDuration of action of moving object

Solution Approach 1:

The housing is divided into two separate pieces: a bottom shell with uniform 1 mm wall thickness and a top connector. This segmentation allows each piece to be optimized independently, achieving the required insulation with thinner walls than a single monolithic housing would require, thus reducing the thermal time constant while maintaining safety compliance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent uses a composite insulation approach by combining the dielectric housing structure with an epoxy coating applied to the temperature responsive element. This composite construction provides the necessary insulation and safety standards while using thinner overall wall thickness, thereby reducing the thermal time constant.

Inventive Principle:

Principle #40Composite materials

2Reliability

If a dual insulation construction is used (dielectric housing with additional insulative coating), then the safety standards are met with thinner housing walls, but the manufacturing process becomes time-consuming and costly due to pre-coating and curing requirements

Engineering Contradiction:

Improvesafety standard complianceVSAvoidmanufacturing efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent merges the insulation function into the housing structure itself by using a uniform 1 mm thick dielectric housing that is molded as a single piece. This eliminates the need for separate pre-coating and curing operations, significantly simplifying the manufacturing process and improving productivity while still meeting safety standards.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent changes the wall thickness parameter from the conventional minimum of 2 mm to a uniform 1 mm, achieved through the two-piece housing design. This parameter change is made possible by the segmented structure that distributes insulation requirements across multiple components, eliminating the need for additional insulative coatings and reducing manufacturing complexity.

Inventive Principle:

Principle #35Parameter changes

3Productivity

If a uniform thin-walled housing (1 mm thickness) is used to reduce material costs and improve thermal response, then the thermal time constant decreases and material costs reduce, but meeting IEC 60335-1 safety standards becomes challenging

Engineering Contradiction:

Improvethermal response speedVSAvoidsafety standard compliance

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The housing is segmented into a bottom shell and top connector, allowing the insulation requirements to be distributed across multiple components. Each component can have uniform 1 mm wall thickness, which is sufficient when combined with the epoxy coating on the temperature element, thereby meeting safety standards while maintaining fast thermal response.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs a composite insulation strategy by combining the thin-walled dielectric housing with an epoxy coating applied to the temperature responsive element. This composite construction provides the necessary insulation for safety compliance while using minimal material thickness, thus maintaining fast thermal response and reducing material costs.

Inventive Principle:

Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution achieves IEC 60335-1 safety standards, maintains a fast thermal time constant, and simplifies manufacturing, while ensuring consistent performance and protection against overvoltage with a blow-hole safety feature.

Implementation Method 1

Conducting portions of the temperature responsive element are covered by an epoxy

Methodology Applied

Scientific EffectDielectric insulation: Dielectric

Implementation Method 2

a temperature responsive element that is received in the housing

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS8734012B2Temperature sensor

Publication Date: 2014.05.27 THERM O DISC INC

AI summary

A temperature sensor includes a plastic bottom shell, a plastic cap mating the plastic shell, and a temperature responsive element mounted to the plastic cap and received in a cavity of the plastic bottom shell. The temperature responsive element is positioned in the plastic bottom shell by the cap. An insulating coating is applied to the temperature responsive element. The insulating coating and the plastic bottom shell provide dual electrical insulation for the temperature responsive element.